More and more bicycles have not only a sprung fork but also a sprung rear section. With rear wheel spring suspension of this type, the design requirements can well exceed those of a motorcycle. In contrast to a motorcycle, the chain of the chain drive is tensioned abruptly rather than continuously in the case a bicycle. Furthermore, a cyclist does not sit still on the seat, particularly when travelling over hilly terrain, and this can amplify undesirable vibrations of the spring system. In particular, when riding uphill “out-of saddle” high-amplitude vibrations or movements at the rear suspension may occur. In addition, the distance between bottom bracket and rear wheel axle changes during deflection in many bicycle suspension designs. As a result, depending on the design parameters of the rear suspension and the chosen gear, the chain is more or less tensioned, elongated or shortened, and the crank and the pedals tend to swivel back or forward somewhat under load. To minimise this so-called pedal kickback, diverse spring designs have already been conceived, which range from a simple driving swing arm through a supported single bar mechanism to what is known as the four-bar mechanism, specifically in the variant of what is known as the Horst link rear section (see, for example, WO 93/13974).
A common drawback of all these systems is that the achievable spring travel is generally restricted to a certain maximum value, if complex special solutions with other specific drawbacks are to be avoided. This is particularly of relevance for new-generation mountain bikes with comparatively big wheel diameters, for example 29 inches instead of the more common 26 inches.